SCIENCE -- September 28, 2012 at 12:17 PM ET
Curiosity Finds Evidence of Ancient Water Flows on Mars
NASA's Curiosity rover found evidence for an ancient, flowing stream on Mars at a few sites, including the rock outcrop pictured here. Image by NASA/JPL-Caltech/MSSS.
NASA's Mars rover Curiosity has found signs of water in the form of gravel from ancient streambeds embedded into conglomerate rock near its landing site. And the size and shape of the stones give us clues to how fast and far the streams may have once flowed.
Such evidence of ancient streams has been found at several sites on Mars, NASA scientists reported on Thursday. Among them, the outcrop pictured above, which the Mars Rover team named Hottah, after Hottah Lake in Canada's Northwest Territories.
"Hottah looks like someone jack-hammered up a slab of city sidewalk, but it's really a tilted block of an ancient streambed," said Mars Science Laboratory Project Scientist John Grotzinger of the California Institute of Technology in Pasadena, according to this NASA report.
In this video, NASA scientist William Dietrich compares patterns created by river fans found in California's Death Valley to similar fans found on Mars. The Martian landscape, he explains, also shows patterns of sunken canyons and sediment deposited by various channels.
"Looking at the entire system, we see that it's a watershed," Dietrich said. "Water has cut a deep canyon, spread sediment across the crater wall and then deposited sediment perhaps as far as the Curiosity rover itself, where we now recognize water-transported gravel.
Curiosity science team member William Dietrich explores the relationship between river fans found in California's Death Valley and similar fans found at the Gale Crater on Mars. Video by NASA Jet Propulsion Laboratory California Institute of Technology.